Built-up roofing



H. H. ROBERTSON.`

BUILT-UP ROOFING.

APPLlcAnN FILED Nov.27, 19m.

1,343,478. Patented June 15,1920.

UNITED STATES PATENT OFFICE.

HAROLD H. ROBERTSON, OF SEWICKLEY, PENNSYLVANIA', ASSIGNOR TO ASPROMET COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION 0F PENNSYLVANIA.

BUILT-UP aooFI'Ne.

Specification of Letters Patent. Patented June 15, 1920.

Application filed November 27, 1918. Serial No. 264,420.

To all whom t may concern.' l

Be it known that I HAROLD H. RonERT- soN, a subject of the King of Great Brltain, residing in Sewickley in thecounty of Allegheny and State of ennsylvania, have invented an Improvement in Built-Up Roofings, of which the following description, in connection with the accompanying draw-V ings, is a specification, like characters on the drawings representing like parts.

The present invention relates to a protective covering especially designed and adapted for vroofs and other relatively fiat parts of a building, and has for its object to provide a superior and more durable protective covering for the. purpose specified.

To this end the protective covering is composed of preferably a plurality of superimposed sheets or layers of paper or felt capable of readily absorbing asphalt or like bituminous compositions, with which said layers are saturated to provide the protec- 'tive covering with a maximum quantity of water repellent material, and a layer or 'sheet of asbestos paper or felt which is saturated with asphalt or other waterproofing material and which is opaque, dense and resistive to the actinic rays of the sun and to the action of acid and alkaline 'fumes and gases, vand which isapplied to and united with the saturated layers of paper or felt to form a protective covering for the said saturated layers.

The felt and asbestos layers may and preferably will be separated from the roof and from each other by layers of asphalt of a higher melting point than the asphalt with which the said layers are saturated, which layers of higher meltin point asphalt serve to cement the fibrous ayers together and increase the Water-repelling properties of the covering. The roof when made ofigypsum, cement or like slabs may and preferably. will be provided with a 'thin primary coat of cold liquid asphalt, which serves to bind together loose particles of gypsum or cement on the surface of the roof and pron 4saturated as well as the cementing asphalt,

ina condition of maximum eiiiciency as a water-repellent for a maximum length of time, with the .result that a superior, and more durable covering for roofs andthe like may be obtained. x

The asbestoslayer may and preferably will haveapplied to it a layer ofcementing asphalt to which a layer of sand or other granular material is applied.

The particular vfeatures of this invention will be pointed out in the claims at the end of this specification.

The drawing represents a portion of a roof provided with a protective covering embodying this invention.

Referring to the drawing a represents a portion of a roof, which may be of wood,

metal or plastic material such as gypsum,-

higher melting'polnt than the saturating asphalt 12 and which maykbe designated ce-v menting asphalt layers, and these saturated wool yfelt layers are then covered by a-layer 14 of opaque relatively dense material, such as-asbestos paper or felt, which is waterproofed inany suitable manner, preferably by saturating the same with asphalt 12, and the, asbestos layer 14 may and preferably Will have applied to it a layer 1,5 of cementing asphalt to which a coating 16 of sand or like granular material is applied.`

It is preferred to first apply to the roof a especially when made of gypsum, cement or like material, athin priming coat 17 of cold liquid asphalt, a portion only of which is shown in the drawing to enable it to be distinguished from the cementing layer 13 applied to it.A In practice the asphalt comprismg applied.

The protective covering describedv forms an effective and superior protection for the the cementing layers 13 is hot when i roof a, as the asphalt or bituminous material is present in a maximum quantity and its Water-repellent properties are available as a protection for the roof for a maximum length of time, owin to the fact that the wool felt layers readlly absorb the asphalt and consequently carry a maximum quantity the roof, and

of the same, and the-layer of asbestos felt or paper, belng opaque, dense, and resistive to fire and to acid and alkali gases and fumes, protects the water-repellent layers of saturating as well as the cementing asphalt from the action of the actinic rays of the sun, from acid .and valkali gases and fumes, and also prevents loss of the volatile ingredient/s in the asphalt. Additional protection is afforded by the gritty layer 15.

It will readily be seen that the individual layers of wool felt and asbestos paper or felt may be prepared in the factory, shipped to the job andl applied one to the other on Wheln. the covering has thus been built up,5 the coating of gritty material may be readily applied thereto, With the result that the roof is provided With a covering Which is fire-resisting, affords superior protection for the roof against the Weather and atmospheric conditions, and Which is of maximum durability.

Claims:

l. A protective covering for roofs and the like comprising a plurality of superimposed layers of wool felt saturated with asphalt, and a layer of asbestos felt saturated with asphalt and superimposed upon the said Wool felt layers, and a layer of gritty material adhesively aiiixed on 'said asbestos layer. A A

2. A 'protective covering for roofs and the like comprising a plurality of superimposed layersof Wool felt saturated With asphalt, and a layer of asbestos felt saturated with asphalt and superimposed upon the said Wool felt layers.

3. A protective covering for roofs andthe like, comprising a layer of relatively high melting point bituminous material, a layer of fibrous material saturatedwith a lower melting point 'bituminous material and applied to said layer of relatively high melting point, ,a layer of relatively high melting point bituminous material applied to said fibrous layer, and a waterproofed and i denser layer of fibrous material which is resistive to acids and alkali fumes and the actinic rays of the sun superimposed on said saturated fibrous layer and cemented.

thereto by the.- interposed layer of relatively high melting point bituminous material.

4. A protective covering for roofs and the like, comprising a priming coat of liquid asphalt, a cementing layer of asphalt applied to said priming coat, a layer of fibrous material saturated 4With asphalt and applied f to the layer of said cementing asphalt, a

layer of cementing asphalt applied to said saturated fibrous layer, and a Waterproofed layer of asbestos felt or paper applied to the second mentioned cementing asphalt layer.

In testimony whereof I have signed my name to this s eciication.

OLD H. ROBERTSON. 

